Metal oxide semiconductor field effect transistor (MOSFET) channels with silicon-germanium or germanium generally have a gate stack that includes a silicon cap on the channel, a high κ dielectric layer on the silicon cap, and a gate electrode on the high kappa dielectric layer. Generally, a silicon cap is required between the channel and the high kappa dielectric layer to provide channel stability over time. Without a silicon cap, unstable germanium oxide or a sub-stoichiometric germanium metal oxide may form at the surface of the channel over time. The formation rate of these oxides may be increased by higher temperatures. These oxides may have dangling bonds and/or oxygen vacancies at the germanium oxide interface and may limit the ability of the gate to control the transistor, resulting in a less efficient transistor. A silicon cap may reduce the formation of these germanium oxides but may not eliminate it or reduce the impact. Therefore, over time, a germanium containing channel may form these oxides, resulting in degraded performance of transistors with germanium containing channels.